Method and system for virtual machine backup

ABSTRACT

Virtual machine backup is described. A backup copy is created of a data set associated with a virtual machine based on a backup schedule. A clone copy is created of the backup copy based on a clone schedule. The clone copy is stored on an external destination node including a disk and/or a tape. A disaster recovery copy may be created of the backup copy and metadata associated with the backup copy based on a checkpoint at an interval. A request to restore the data set may be received. The data set may be restored based on the backup copy, the clone copy, or the disaster recovery copy.

BACKGROUND

If a software error corrupts a database, or if erroneous data updatesthe database, a database administrator may restore the database to aprevious uncorrupted state that does not include the corrupted orerroneous data. A backup application executes a backup operation eitheroccasionally or continuously to enable this restoration, storing a copyof each desired database state (the values of its data and these values'embedding in the database's data structures) within dedicated backupfiles. When the database administrator decides to return the database toa previous state, the database administrator specifies the desiredprevious state by identifying a desired point in time when the databasewas in this state, and instructs the backup application to execute arestore operation to restore a copy of the corresponding backup filesfor that state to the database. An additional copy that is made of thecopy of the backup files and stored separately from the backup files maybe referred to as a clone copy of the backup files.

A virtual machine is a software implementation of a computer thatexecutes programs like a physical machine. A system virtual machineprovides a complete system platform that supports the execution of acomplete operating system, and usually emulates an existingarchitecture. Multiple instances of virtual machines lead to moreefficient use of computing resources, both in terms of energyconsumption and cost effectiveness, known as hardware virtualization,the key to a cloud computing environment. Similar to other databases,backup copies are made of virtual machine databases to enable arestoration of the virtual machine database in the event of corruptionor an erroneous update to the virtual machine database.

BRIEF DESCRIPTION OF THE DRAWINGS

Advantages of the subject matter claimed will become apparent to thoseskilled in the art upon reading this description in conjunction with theaccompanying drawings, in which like reference numerals have been usedto designate like elements, and in which:

FIG. 1 is a block diagram illustrating an example hardware device inwhich the subject matter may be implemented;

FIG. 2 illustrates a block diagram of an example system for virtualmachine backup, under an embodiment; and

FIG. 3 is a flowchart that illustrates a method of virtual machinebackup, under an embodiment.

DETAILED DESCRIPTION

In the prior art, a virtual machine backup tool can create a backup copyof a virtual machine database, but the backup copy may be lost if thevirtual machine backup tool and/or the backup copy was corrupted.Furthermore, many virtual machine backup tools may be limited to the useof only a small number of internal proxy agents that can execute dataprotection tasks for virtual machine databases because many virtualmachine backup tools have a limited storage capacity.

Embodiments herein provide virtual machine backup. A backup copy iscreated of a data set associated with a virtual machine based on abackup schedule. For example, a virtual machine backup appliance createsand stores a backup copy of a virtual machine's data set whenever aspecified amount of modifications have been made to the data set. Aclone copy is created of the backup copy based on a clone schedule. Forexample, the virtual machine backup appliance periodically creates aclone copy of the backup copy. The clone copy is stored on an externaldestination node including a disk and/or a tape. For example, thevirtual machine backup appliance stores the clone copy on an externaldisk, thereby protecting a copy of the data set even if the virtualmachine backup appliance and/or the backup copy of the data set arecorrupted. A disaster recovery copy may be created of the backup copyand metadata associated with the backup copy based on a checkpoint at aninterval. For example, a disaster recovery copy is made of the backupcopy based on checkpoints at regular intervals. A request to restore thedata set may be received. For example, the virtual machine backupappliance receives a request to restore the data set to the virtualmachine. The data set may be restored based on the backup copy, theclone copy, or the disaster recovery copy. For example, the virtualmachine backup appliance restores the data set to the virtual machinefrom either the backup copy, the clone copy, or the disaster recoverycopy, depending on the availability and creation time of each copy. Thevirtual machine backup appliance provides full enterprise levelprotection of data for all of an enterprise's virtual machines.

Prior to describing the subject matter in detail, an exemplary hardwaredevice in which the subject matter may be implemented shall first bedescribed. Those of ordinary skill in the art will appreciate that theelements illustrated in FIG. 1 may vary depending on the systemimplementation. With reference to FIG. 1, an exemplary system forimplementing the subject matter disclosed herein includes a hardwaredevice 100, including a processing unit 102, memory 104, storage 106,data entry module 108, display adapter 110, communication interface 112,and a bus 114 that couples elements 104-112 to the processing unit 102.

The bus 114 may comprise any type of bus architecture. Examples includea memory bus, a peripheral bus, a local bus, etc. The processing unit102 is an instruction execution machine, apparatus, or device and maycomprise a microprocessor, a digital signal processor, a graphicsprocessing unit, an application specific integrated circuit (ASIC), afield programmable gate array (FPGA), etc. The processing unit 102 maybe configured to execute program instructions stored in memory 104and/or storage 106 and/or received via data entry module 108.

The memory 104 may include read only memory (ROM) 116 and random accessmemory (RAM) 118. Memory 104 may be configured to store programinstructions and data during operation of device 100. In variousembodiments, memory 104 may include any of a variety of memorytechnologies such as static random access memory (SRAM) or dynamic RAM(DRAM), including variants such as dual data rate synchronous DRAM (DDRSDRAM), error correcting code synchronous DRAM (ECC SDRAM), or RAMBUSDRAM (RDRAM), for example. Memory 104 may also include nonvolatilememory technologies such as nonvolatile flash RAM (NVRAM) or ROM. Insome embodiments, it is contemplated that memory 104 may include acombination of technologies such as the foregoing, as well as othertechnologies not specifically mentioned. When the subject matter isimplemented in a computer system, a basic input/output system (BIOS)120, containing the basic routines that help to transfer informationbetween elements within the computer system, such as during start-up, isstored in ROM 116.

The storage 106 may include a flash memory data storage device forreading from and writing to flash memory, a hard disk drive for readingfrom and writing to a hard disk, a magnetic disk drive for reading fromor writing to a removable magnetic disk, and/or an optical disk drivefor reading from or writing to a removable optical disk such as a CDROM, DVD or other optical media. The drives and their associatedcomputer-readable media provide nonvolatile storage of computer readableinstructions, data structures, program modules and other data for thehardware device 100.

It is noted that the methods described herein can be embodied inexecutable instructions stored in a computer readable medium for use byor in connection with an instruction execution machine, apparatus, ordevice, such as a computer-based or processor-containing machine,apparatus, or device. It will be appreciated by those skilled in the artthat for some embodiments, other types of computer readable media may beused which can store data that is accessible by a computer, such asmagnetic cassettes, flash memory cards, digital video disks, Bernoullicartridges, RAM, ROM, and the like may also be used in the exemplaryoperating environment. As used here, a “computer-readable medium” caninclude one or more of any suitable media for storing the executableinstructions of a computer program in one or more of an electronic,magnetic, optical, and electromagnetic format, such that the instructionexecution machine, system, apparatus, or device can read (or fetch) theinstructions from the computer readable medium and execute theinstructions for carrying out the described methods. A non-exhaustivelist of conventional exemplary computer readable medium includes: aportable computer diskette; a RAM; a ROM; an erasable programmable readonly memory (EPROM or flash memory); optical storage devices, includinga portable compact disc (CD), a portable digital video disc (DVD), ahigh definition DVD (HD-DVD™), a BLU-RAY disc; and the like.

A number of program modules may be stored on the storage 106, ROM 116 orRAM 118, including an operating system 122, one or more applicationsprograms 124, program data 126, and other program modules 128. A usermay enter commands and information into the hardware device 100 throughdata entry module 108. Data entry module 108 may include mechanisms suchas a keyboard, a touch screen, a pointing device, etc. Other externalinput devices (not shown) are connected to the hardware device 100 viaexternal data entry interface 130. By way of example and not limitation,external input devices may include a microphone, joystick, game pad,satellite dish, scanner, or the like. In some embodiments, externalinput devices may include video or audio input devices such as a videocamera, a still camera, etc. Data entry module 108 may be configured toreceive input from one or more users of device 100 and to deliver suchinput to processing unit 102 and/or memory 104 via bus 114.

A display 132 is also connected to the bus 114 via display adapter 110.Display 132 may be configured to display output of device 100 to one ormore users. In some embodiments, a given device such as a touch screen,for example, may function as both data entry module 108 and display 132.External display devices may also be connected to the bus 114 viaexternal display interface 134. Other peripheral output devices, notshown, such as speakers and printers, may be connected to the hardwaredevice 100.

The hardware device 100 may operate in a networked environment usinglogical connections to one or more remote nodes (not shown) viacommunication interface 112. The remote node may be another computer, aserver, a router, a peer device or other common network node, andtypically includes many or all of the elements described above relativeto the hardware device 100. The communication interface 112 mayinterface with a wireless network and/or a wired network. Examples ofwireless networks include, for example, a BLUETOOTH network, a wirelesspersonal area network, a wireless 802.11 local area network (LAN),and/or wireless telephony network (e.g., a cellular, PCS, or GSMnetwork). Examples of wired networks include, for example, a LAN, afiber optic network, a wired personal area network, a telephony network,and/or a wide area network (WAN). Such networking environments arecommonplace in intranets, the Internet, offices, enterprise-widecomputer networks and the like. In some embodiments, communicationinterface 112 may include logic configured to support direct memoryaccess (DMA) transfers between memory 104 and other devices.

In a networked environment, program modules depicted relative to thehardware device 100, or portions thereof, may be stored in a remotestorage device, such as, for example, on a server. It will beappreciated that other hardware and/or software to establish acommunications link between the hardware device 100 and other devicesmay be used.

It should be understood that the arrangement of hardware device 100illustrated in FIG. 1 is but one possible implementation and that otherarrangements are possible. It should also be understood that the varioussystem components (and means) defined by the claims, described below,and illustrated in the various block diagrams represent logicalcomponents that are configured to perform the functionality describedherein. For example, one or more of these system components (and means)can be realized, in whole or in part, by at least some of the componentsillustrated in the arrangement of hardware device 100. In addition,while at least one of these components are implemented at leastpartially as an electronic hardware component, and therefore constitutesa machine, the other components may be implemented in software,hardware, or a combination of software and hardware. More particularly,at least one component defined by the claims is implemented at leastpartially as an electronic hardware component, such as an instructionexecution machine (e.g., a processor-based or processor-containingmachine) and/or as specialized circuits or circuitry (e.g., discretelogic gates interconnected to perform a specialized function), such asthose illustrated in FIG. 1. Other components may be implemented insoftware, hardware, or a combination of software and hardware. Moreover,some or all of these other components may be combined, some may beomitted altogether, and additional components can be added while stillachieving the functionality described herein. Thus, the subject matterdescribed herein can be embodied in many different variations, and allsuch variations are contemplated to be within the scope of what isclaimed.

In the description that follows, the subject matter will be describedwith reference to acts and symbolic representations of operations thatare performed by one or more devices, unless indicated otherwise. Assuch, it will be understood that such acts and operations, which are attimes referred to as being computer-executed, include the manipulationby the processing unit of data in a structured form. This manipulationtransforms the data or maintains it at locations in the memory system ofthe computer, which reconfigures or otherwise alters the operation ofthe device in a manner well understood by those skilled in the art. Thedata structures where data is maintained are physical locations of thememory that have particular properties defined by the format of thedata. However, while the subject matter is being described in theforegoing context, it is not meant to be limiting as those of skill inthe art will appreciate that various of the acts and operation describedhereinafter may also be implemented in hardware.

To facilitate an understanding of the subject matter described below,many aspects are described in terms of sequences of actions. At leastone of these aspects defined by the claims is performed by an electronichardware component. For example, it will be recognized that the variousactions can be performed by specialized circuits or circuitry, byprogram instructions being executed by one or more processors, or by acombination of both. The description herein of any sequence of actionsis not intended to imply that the specific order described forperforming that sequence must be followed. All methods described hereincan be performed in any suitable order unless otherwise indicated hereinor otherwise clearly contradicted by context. In an embodiment, thecomputer system 100 includes one or more methods for a data protectionpolicy generator.

In the prior art, a backup copy of a virtual machine's data set may belost if the virtual machine backup tool and/or the backup copy wascorrupted. Embodiments herein provide virtual machine backup.

FIG. 2 illustrates a block diagram of a system that implements virtualmachine backup, under an embodiment. As shown in FIG. 2, system 200 mayillustrate a cloud computing environment in which data, applications,services, and other resources are stored and delivered through shareddata-centers and appear as a single point of access for the users. Thesystem 200 may also represent any other type of distributed computernetwork environment in which servers control the storage anddistribution of resources and services for different client users.

In an embodiment, the system 200 represents a cloud computing systemthat includes a first client 202 and a second client 204; and a firstserver 206, a second server 208, a third server 210, and a fourth server212 that are provided by a hosting company. The clients 202-204 and theservers 206-212 communicate via a network 214. Although FIG. 2 depictsthe system 200 with two clients 202-204, four servers 206-212, and onenetwork 214, the system 200 may include any number of clients 202-204,servers 206-212, and networks 214. The clients 202-204 and the servers206-212 may each be substantially similar to the system 100 depicted inFIG. 1.

The first server 206 includes a first virtual machine 216 and a secondvirtual machine 218. The first virtual machine includes a data set 220.The second server 208 includes a virtual machine backup appliance 222,and may include a third virtual machine 226. The virtual machine backupappliance 222 may also be a virtual machine. The virtual machine backupappliance 222 includes internal proxy agents 224 and supports externalproxy agents 228, which are internal proxy agents for the third virtualmachine 226. FIG. 2 depicts the system elements 216-220 residingcompletely on the first server 206 with the system elements 222-228residing completely on the second server 208. However, the systemelements 216-228 may reside completely on the first server 206,completely on the second server 208, or in any combination of partiallyon the first server 206, partially on the second server 208, partiallyon the third server 210, and partially on the fourth server 212.

A data protection administrator uses the first client 202 to instructthe virtual machine backup appliance 222 to protect the data set 220used by the first virtual machine 216, which is accessed by a user viathe second client 204 and provided by the first server 206, by storingvarious copies of the data set 220 on the servers 208-212.

The virtual machine backup appliance 222 receives a selection from thefirst client 202 to protect the data set 220 accessed by the secondclient 204 via the first virtual machine 216 in the first server 206.For example, the virtual machine backup appliance 222 receives aselection to create a backup copy of the data set 220 in the firstserver 206, and store the backup copy via the second server 208, basedon a backup schedule. The first source, such as the first server 206,may include multiple source nodes. For example, the first virtualmachine 216 may store the data set 220 on a disk associated with thefirst server 206. A data protection administrator may use the virtualmachine backup appliance 222 to specify a query for data sets, andidentify the response to the query as the data set to be copied. Thefirst destination, such as the second server 208, may include multipledestination nodes, and the multiple destination nodes may include a diskdestination node, a tape destination node, and/or a destination nodethat is a combination of disks and tapes. For example, one of theinternal proxy agents 224 or one of the external proxy agents 228 maystore the backup copy of the data set 220 on a disk, on a tape, orpartly on a disk and partly on a tape associated with the second server208.

In the prior art, many virtual machine backup tool may be limited to asmall number of internal proxy agents due to limitations on the size ofthe code that provides the virtual machine backup tool, which means thatthe virtual machine backup tool is limited to executing a small numberof concurrent data protection tasks. The virtual machine backupappliance 222 is deployed as a downloadable open virtualizationappliance file, a single compressed file that contains an operatingsystem image, packages, boot scripts, etc. While this deploymentlimitation on code size also limits the virtual machine backup appliance222 to a small number of the internal proxy agents 224, the virtualmachine backup appliance 222 may also support an unlimited number of theexternal proxy agents 228. The external proxy agents 228 are deployed aspart of the third virtual machine 226, which is also a downloadable openvirtualization appliance file, which can be deployed and registered withthe virtual machine backup appliance 222, such that the external proxyagents 228 may be added to the available proxy agent pool for thevirtual machine backup appliance 222.

A data protection administrator may use the virtual machine backupappliance 222 to specify a priority for storing copies of data ondestination nodes, such as storing only on disks, or storing on disksbefore storing on a combination of disks and tapes. Additionally, a dataprotection administrator may use the virtual machine backup appliance220 to specify the options for data to be encrypted, deduplicated,and/or compressed while being transmitted from a source, and the optionsfor data to be decrypted and/or decompressed when stored on adestination. Data deduplication significantly reduces backup time byonly storing unique daily changes, while always maintaining daily fullbackups for immediate single-step restore. The transmission ofdeduplicated backup sends only changed blocks, thereby reducing networktraffic.

A backup application may receive a selection from the first client 202to protect the data set 220 accessed by the second client 204 via thefirst virtual machine 216 in the first server 206. For example, aNetWorker® backup application receives a selection to create a clonecopy of the data set 220 from a second source, the second server 208,and store the clone copy in the second destination, the third server210, based on a clone schedule. The second source may include multiplesource nodes, and the multiple source nodes may include a disk sourcenode, a tape source node, and/or a source node that is a combination ofdisks and tapes. For example, the second server 208 may store the backupcopy of the data set 220 on a disk, on a tape, or partly on a disk andpartly on a tape. Similarly, the second destination may include multipledestination nodes, and the multiple destination nodes may include a diskdestination node, a tape destination node, and/or a destination nodethat is a combination of disks and tapes. For example, one of theinternal proxy agents 224 or one of the external proxy agents 228 maystore the clone copy of the data set 220 on a disk, on a tape, or partlyon a disk and partly on a tape associated with the third server 210.

EMC Corporation's NetWorker® backup application is a suite of enterpriselevel data protection software that unifies and automates backup totape, disk-based, and flash-based storage media across physical andvirtual environments for granular and disaster recovery. Cross-platformsupport is provided for many environments, including Microsoft Windows®.A central NetWorker® server manages a data zone that contains backupclients and NetWorker® storage nodes that access the backup media. TheNetWorker@ management console software provides a graphic user interfacefor functions such as client configuration, policy settings, schedules,monitoring, reports, and daily operations for deduplicated andnon-deduplicated backups. The core NetWorker® software backs up clientfile systems and operating system environment. Add-on database andapplication modules provide backup services for products such asMicrosoft® Exchange Server. Client backup data can be sent to a remoteNetWorker® storage node or stored on a locally attached device by theuse of a dedicated storage node. EMC Corporation's NetWorker® modulesfor Microsoft® applications supports Microsoft® products such asMicrosoft® Exchange, Microsoft® Sharepoint, Microsoft® SQL Server, andMicrosoft® Hyper-V servers. The virtual machine backup appliance 222 maybe deployed as a module that plugs into the NetWorker® backupapplication, which a data protection administrator may access to monitorand control any number of virtual machine backup appliances 222. Thecapability of monitoring and controlling any number of virtual machinebackup appliances 222, combined with the capability of each virtualmachine backup appliance 222 to support multiple external proxy agents226 provides the NetWorker® backup application with the capacity tooffer full enterprise level protection of data for all of anenterprise's virtual machines.

The virtual machine backup appliance 222 may receive an additionalselection to protect the data set 220 accessed by the second client 204via the first virtual machine 216 in the first server 206. For example,the virtual machine backup appliance 222 receives a selection to createa disaster recovery copy of the data set 220 and the associated metadatafrom the third source, the third server 210, and store the disasterrecovery copy in the third destination, the fourth server 212, based oncheckpoints at regular intervals. The third source may include multiplesource nodes, and the multiple source nodes may include a disk sourcenode, a tape source node, and/or a source node that is a combination ofdisks and tapes. For example, the third server 210 may store the clonecopy of the data set 220 on a disk, on a tape, or partly on a disk andpartly on a tape. Similarly, the third destination may include multipledestination nodes, and the multiple destination nodes may include a diskdestination node, a tape destination node, and/or a destination nodethat is a combination of disks and tapes. For example, the VirtualMachine Backup Appliance 222 executing on the second server 208 maystore the disaster recovery copy of the data set 220 and the associatedmetadata on a disk, on a tape, or partly on a disk and partly on a tapeassociated with the fourth server 212. The disaster recovery copy of thedata set 220 may be based on checkpoints that the Virtual Machine BackupAppliance 222 created at regular intervals. The Virtual Machine BackupAppliance 222 automatically rolls back the data set 220 to a certaincheckpoint during a power up if the preceding shutdown of the firstvirtual machine 216 was abnormal. Furthermore, an administrator mayselect to execute a manual rollback to a certain checkpoint selected bythe administrator.

A virtual machine center application is executed by a server, such asthe second server 208, to provide a centralized and extensible platformfor managing virtual infrastructure. This managing of virtual machineenvironments enables information technology administrators to havesimple and automated control over a virtual environment to deliverinfrastructure. A virtual machine center server provides centralizedmanagement of virtualized hosts and virtual machines from a singleconsole, and gives administrators visibility into the configuration ofall the critical components of a virtual infrastructure, all from oneplace. With a virtual machine center server, virtual environments areeasier to manage, as a single administrator can manage hundreds ofworkloads, more than doubling typical productivity in managing physicalinfrastructure. The virtual machine backup appliance 222 is deployed asa module that may plug into the virtual machine center application,which enables the virtual machine backup appliance 222 to access each ofthe virtual machines monitored and controlled by the virtual machinecenter application. An administrator may use the virtual machine centerapplication to manually initiate a backup copy and/or a clone copy of adata set via the virtual machine backup appliance 222.

Data protection administrators may use the virtual machine backupappliance 222 to generate a specific policy based on the specific needsof a customer, and reuse that policy for customers with similar needs.For example, a data protection administrator may use the virtual machinebackup appliance 222 to generate a “gold” policy, a “platinum” policy,and a “silver” policy for VMware® clients. The gold policy can specifyto store 2 backup copies for each VMware® client onto a first disk for 6months, store a clone of the backup copies on a second disk for 1 year,and store a secondary clone of the backup copies on a tape for 5 years.In this example, the data protection administrator that used the virtualmachine backup appliance 222 to generate the gold policy for a specificset of VMware® clients may later apply another instance of the same goldpolicy to a different set of VMware® clients. Similarly, the dataprotection administrator may apply another instance of the same platinumpolicy to a different set of VMware® clients. The virtual machine backupappliance 222 provides full enterprise level protection of data for allof an enterprise's virtual machines

FIG. 3 is a flowchart that illustrates a method of virtual machinebackup. Flowchart 300 illustrates method acts illustrated as flowchartblocks for certain steps involved in and/or between the clients 202-204and/or the servers 206-212 of FIG. 2.

A backup copy is created of a data set associated with a virtual machinebased on a backup schedule, act 302. For example, the virtual machinebackup appliance 222 creates and stores a backup copy of the data set220 for the first virtual machine 216 whenever the first virtual machine216 has made modifications to the data set 220.

A clone copy is created of the backup copy based on a clone schedule,act 304. For example, the virtual machine backup appliance 222periodically creates a clone copy of the backup copy.

The clone copy is stored on an external destination node including adisk and/or a tape, act 306. For example, the virtual machine backupappliance 222 stores the clone copy on an external disk associated withthe third server 210, thereby protecting a copy of the data set 220 evenif the virtual machine backup appliance 222 and/or the backup copy ofthe data set 220 stored on the second server 208 is corrupted.

A disaster recovery copy is optionally created of the backup copy andmetadata associated with the backup copy based on a checkpoint at aninterval, act 308. For example, the Virtual Machine Backup Appliance 222makes a disaster recovery copy of the backup copy stored via the secondserver 208 and stores the disaster recovery copy via the fourth server212, based on checkpoints at regular intervals.

A request to restore the data set is optionally received, act 310. Forexample, the virtual machine backup appliance 222 receives a request torestore the data set 220 to the first virtual machine 216.

The data set is optionally restored based on the backup copy, the clonecopy, or the disaster recovery copy, act 312. For example, the virtualmachine backup appliance 222 restores the data set 220 to the firstvirtual machine 216 from either the backup copy stored via the secondserver 208, the clone copy stored via the third server 210, or thedisaster recovery copy stored via the fourth server 212, depending onthe availability and creation time of each copy. For example, thevirtual machine backup appliance 222 may typically select to restore thedata set 220 to the first virtual machine 216 from the backup copystored via the second server 208. However, if the virtual machine backupappliance 222 determines that the backup copy stored via the secondserver 208 is corrupted, the virtual machine backup appliance 222 mayselect between the clone copy stored via the third server 210 and thedisaster recovery copy stored via the fourth server 212, depending onthe most recent creation time of each corresponding copy. Even if thevirtual machine backup appliance 222 selects the clone copy stored viathe third server 210 or the disaster recovery copy stored via the fourthserver 212, a user requesting the recovery via the first client 202participates in a single step recovery process, as the user does nothave to request the separate loading of any storage medium used forlong-term data retention, such as a tape storage. Furthermore, thevirtual machine backup appliance 222 may restore the data set 220 to thefirst virtual machine 216 based on a file level data set, such as theselective restoration of specific files identified by the user via thefirst client 202, without the need to restore all of the other filesremaining in the data set 220 to the first virtual machine 216.

Although FIG. 3 depicts the acts 302-312 occurring in a specific order,the acts 302-312 may occur in another order. Executing the flowchart 300enables virtual machine backup that provides full enterprise levelprotection of data for all of an enterprise's virtual machines.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the subject matter (particularly in the context ofthe following claims) are to be construed to cover both the singular andthe plural, unless otherwise indicated herein or clearly contradicted bycontext. Recitation of ranges of values herein are merely intended toserve as a shorthand method of referring individually to each separatevalue falling within the range, unless otherwise indicated herein, andeach separate value is incorporated into the specification as if it wereindividually recited herein. Furthermore, the foregoing description isfor the purpose of illustration only, and not for the purpose oflimitation, as the scope of protection sought is defined by the claimsas set forth hereinafter together with any equivalents thereof entitledto. The use of any and all examples, or exemplary language (e.g., “suchas”) provided herein, is intended merely to better illustrate thesubject matter and does not pose a limitation on the scope of thesubject matter unless otherwise claimed. The use of the term “based on”and other like phrases indicating a condition for bringing about aresult, both in the claims and in the written description, is notintended to foreclose any other conditions that bring about that result.No language in the specification should be construed as indicating anynon-claimed element as essential to the practice of the invention asclaimed.

Preferred embodiments are described herein, including the best modeknown to the inventor for carrying out the claimed subject matter. Ofcourse, variations of those preferred embodiments will become apparentto those of ordinary skill in the art upon reading the foregoingdescription. The inventor expects skilled artisans to employ suchvariations as appropriate, and the inventor intends for the claimedsubject matter to be practiced otherwise than as specifically describedherein. Accordingly, this claimed subject matter includes allmodifications and equivalents of the subject matter recited in theclaims appended hereto as permitted by applicable law. Moreover, anycombination of the above-described elements in all possible variationsthereof is encompassed unless otherwise indicated herein or otherwiseclearly contradicted by context.

What is claimed is:
 1. A system for virtual machine backup, the systemcomprising: one or more processors; a processor-based application storedon a non-transitory computer readable medium, which when executed on acomputer, will cause the one or more processors to: create a backup copyof a data set associated with a virtual machine based on a backupschedule; create a clone copy of the backup copy based on a cloneschedule; and store the clone copy on an external destination nodecomprising at least one of a disk and a tape.
 2. The system of claim 1,wherein the processor-based application will further cause the one ormore processors to: receive a request to restore the data set; andrestore the data set based on one of the backup copy and the clone copy.3. The system of claim 1, wherein the processor-based application willfurther cause the one or more processors to: create a disaster recoverycopy of the backup copy and metadata associated with the backup copybased on a checkpoint at an interval; receive a request to restore thedata set; and restore the data set based on the disaster recovery copy.4. The system of claim 1, wherein the backup schedule and the cloneschedule comprise a data protection policy.
 5. The system of claim 1,wherein at least one of creating the backup copy of the data setcomprises at least one of an internal proxy agent creating the backupcopy of the data set and an external proxy agent creating the backupcopy of the data set, and wherein creating the clone copy of the backupcopy comprises at least one of the internal proxy agent creating theclone copy of the backup copy and the external proxy agent creating theclone copy of the backup copy.
 6. The system of claim 1, wherein atleast one of creating the backup copy of the data set comprises creatinga deduplicated backup copy of the data set, and wherein creating theclone copy of the backup copy comprises creating a deduplicated clonecopy of the backup copy.
 7. The system of claim 1, wherein the data setcomprises a file level data set.
 8. A computer-implemented method forvirtual machine backup, the method comprising: creating a backup copy ofa data set associated with a virtual machine based on a backup schedule;creating a clone copy of the backup copy based on a clone schedule; andstoring the clone copy on an external destination node comprising atleast one of a disk and a tape.
 9. The method of claim 8, wherein themethod further comprises: receiving a request to restore the data set;and restoring the data set based on one of the backup copy and the clonecopy.
 10. The method of claim 8, wherein the method further comprises:creating a disaster recovery copy of the backup copy and metadataassociated with the backup copy based on a checkpoint at an interval;receiving a request to restore the data set; and restoring the data setbased on the disaster recovery copy.
 11. The method of claim 8, whereinthe backup schedule and the clone schedule comprise a data protectionpolicy.
 12. The method of claim 8, wherein at least one of creating thebackup copy of the data set comprises at least one of an internal proxyagent creating the backup copy of the data set and an external proxyagent creating the backup copy of the data set, and wherein creating theclone copy of the backup copy comprises at least one of the internalproxy agent creating the clone copy of the backup copy and the externalproxy agent creating the clone copy of the backup copy.
 13. The methodof claim 8, wherein at least one of creating the backup copy of the dataset comprises creating a deduplicated backup copy of the data set, andwherein creating the clone copy of the backup copy comprises creating adeduplicated clone copy of the backup copy.
 14. The method of claim 8,wherein the data set comprises a file level data set.
 15. A computerprogram product, comprising a non-transitory computer-readable mediumhaving a computer-readable program code embodied therein, thecomputer-readable program code adapted to be executed by one or moreprocessors to implement a method for virtual machine backup, the methodcomprising: creating a backup copy of a data set associated with avirtual machine based on a backup schedule; creating a clone copy of thebackup copy based on a clone schedule; and storing the clone copy on anexternal destination node comprising at least one of a disk and a tape.16. The computer program product of claim 15, wherein the method furthercomprises: receiving a request to restore the data set; and restoringthe data set based on one of the backup copy and the clone copy.
 17. Thecomputer program product of claim 15, wherein the method furthercomprises: creating a disaster recovery copy of the backup copy andmetadata associated with the backup copy based on a checkpoint at aninterval; receiving a request to restore the data set; and restoring thedata set based on the disaster recovery copy.
 18. The computer programproduct of claim 15, wherein the backup schedule and the clone schedulecomprise a data protection policy.
 19. The computer program product ofclaim 15, wherein at least one of creating the backup copy of the dataset comprises at least one of an internal proxy agent creating thebackup copy of the data set and an external proxy agent creating thebackup copy of the data set, and wherein creating the clone copy of thebackup copy comprises at least one of the internal proxy agent creatingthe clone copy of the backup copy and the external proxy agent creatingthe clone copy of the backup copy.
 20. The computer program product ofclaim 15, wherein at least one of creating the backup copy of the dataset comprises creating a deduplicated backup copy of the data set, andwherein creating the clone copy of the backup copy comprises creating adeduplicated clone copy of the backup copy.